1. Field of the Invention
The present invention relates to a server, a client apparatus, a program and a download method, which distribute or download a file such as moving images over a network.
2. Description of the Related Art
Heretofore, in the case in which a client apparatus acquires a file from a server, the client apparatus makes access to the server having the file stored therein as the client apparatus is triggered by some event (for example, a user manipulation, or an application using a timer function). However, since it is difficult for a service provider to control the events on the client side to be a trigger, there is a problem that files may not be acquired at the point at which a large number of client apparatuses make access to a server for concentration of access and the access exceeds the capacity of the server or a network. Particularly, this problem tends to occur proportionately with increases in the file size and the number of client apparatuses.
In order to avoid this problem, many service providers (server administrators) allocate various resources (servers and network resources) in consideration of traffic peaks. However, when resources are allocated all the time to manage traffic peaks, it means that excess resources are carried in the periods other than peak periods, which leads to increases in system construction initial costs/service costs. In addition, from the viewpoint of service providers (server administrators), since the occurrence of access triggered by a user manipulation is unpredictable and uncontrollable, the service providers (server administrators) are forced to manage systems so that services can be provided all the time.
JP-A-2006-135811 (Patent Reference 1) discloses a distributed system in which servers including a management server are provided other than a server providing moving images (see claim 1 of the Reference).